Hinge pin, retainer pin, and the like provided with self-locking means



Aug. 14, 1945. J. MARTIN 2,382,166

A HINGE PIN, RETAINER PIN, AND THE' LIKE PROVIDED WITH SELF-LOCKING'MEANS Filed Aprilv 14, 1944 A ttorney Patented Aug. 14, 1945 HINGE PIN,RETAINER PIN, AND THE LIKE PROVIDED WITH SELF-LOCKING MEANS JamesMartin, Higher Denham, near Uxbridge, England Application April 14,1944, Serial No. 531,108 In Great Britain September 7, 1943 4 Claims.

This invention relates to hinge pins, retainer pins and the likeprovided with self-locking means which function automatically to providean abutment normally preventing removal or axial displacement of thepin. or the like when it has been inserted the predetermined requisiteextent into elements being coupled by the pin or the like. The inventionis particularly useful where it is required to obtain a quick-releaselocking action, e. g. as with lynch pins, pins for connecting magazineto gun mountings, hinging together control elements in aircraft and formultitudinous other purposes. The chief object of the invention is toprovide a locking device which is cheap and simple to manufacture inlarge quantities and easily assembled with hollow pins, studs, bolts andthe like. Another object of this invention is to provide a resilientselflocking device entailing vthe minimum number of parts, and a furtherobject of the invention is to avoid the necessity of extraneous tmentsto the pin or the like for locating and spring loading an abutment.member which is urged automatically to the stop or locking positionrelatively to the pin or the like.

According to this invention self-locking means is intended for use withhollow, bored or slotted pins or the like and comprises an abutmentadapted to be projected radially through the stem, shank or the like ofthe pin and supported by a length of resilient wire or rod adapted to besecured in the pin or the like in a direction substantiallyperpendicular to the radial direction of movement of said abutmentrelatively to the pin.

Inthe preferred form of the present invention a hinge pin, retainer pinor the like provided with self-locking means comprises a tubular p inwith a hole or slot in its periphery, a plunger sldable through suchhole or slot, and a length of resilient wire or rod engaged at one endas a push t in a bore formed in one end of the pin in prolongation ofthe hollow of the pin and fitted in the said plunger at its other end,said wire or rod urging the plunger beyond the periphery of the pin andresiliently opposing inward radial movement of the plunger, the outerend of the plunger being radiused or bevelled to permit insertion of thepin in the appropriate elements to be coupled by the pin.

In order that the invention may be clearly understood and readilycarried into effect, drawing is appended hereto illustrating embodimentsthereof, and wherein,

Fig. 1 is a longitudinal sectional view of a plain cylindrical pin withone form of locking device fitted therein.

Fig. 2 is an end elevation of Fig. 1 looking at the open end of the pin.l

Fig. 3 is a perspective View showing the separated elements of the pinwith self-locking means, wherein it will be seen that the completedevice consists of a very few simple elements, and

Figs. 4 and 5 show alternative types of pins and plungers.

Referring to the drawing the pin l can have any suitable externalconfiguration and can be used for multitudinous purposes where it isrequired to couple together elements apertured to receive the pin, thepin being hollow for the predominating portion of its length and closedby a solid end portion 2 which normally would be formed with a head 3.In the examples shown the pin is a parallel cylindrical pin adapted toact as a hinge pin, fastening member or the like vand near its open endit is formed' with an aperture 4 in its periphery to receive a plungeror detent engaging piece 5, the open end preferably having a bevel ortaper 6 to facilitate insertion of the pin in the appropriate hole, andif desired this taper can extend to the aperture 4.

The plunger 5 is shaped to t the aperture with the minimum easy workingclearance so that it is free to rise and fall in such aperture and it ispreferably shaped so that it will pass completely through the aperture.The plunger is held in its normal position slightly projecting beyondthe periphery of the pin I by resilient means which is inter-connectedwith the plunger and with the pin, such resilient means being of anextremely simple and easily produced form and not requiring fasteningmeans additional to such inter-connection to retain it in operativeposition. For this purpose said resilient means comprises a short lengthof suitable gauge steel or other suitable resilient wire or thin rod 1one end of which is a push fit in the pin I so that it extends along theinterior of the pin preferably with its axis in a plane radial inrelation to the pin.

The wire or rod 1 is secured against axial displacement relatively tothe pin l once it is located in the pin and plunger by reason of ithaving imparted to it a slight bend between its ends leaving one limb'la parallel with the axis of the pin for a push-fit engagement in anarrow bore 8 in the solid part 2 of the pin in coaxial prolongationwith the hollow of the pin, and a limb 'lb which is passed at its freeend as a push t through an eye 9 in the plunger 5, its extremity 1bwhich engages in and projects through the plunger preferably beingparallel with the limb 1a engaged in the bore 8, so that in itspreferred form the member 1 is slightly bent at two positions betweenits ends to provide two parallel end parts joined by a relativelyslightly inclined median part.

y The part 1a of the member 1 which fits in the bore 8 is preferablyformed with a conical point 1e to facilitate insertion into such bore,and for the same reason it is preferred to flare the open end of thebore 8 by a conical end wall l0 at the inner end of the hollow of thepin.

'I'he members 1 can be produced easily in large quantities by feedingthe wire through a cutter having dies which impart the beforesaid slightdouble bend to the members 1 as they are sheared from the length ofwire. i Y

The plunger 5 is preferably shaped to Vform a cam-like part projectingfrom the periphery of the pin l so that the pin can be pushed homewithout the plunger preventing insertion of the pin in the appropriatehole, the wire or rod member 1 urging the plunger to the protrudingposition immediately the plunger has passed through the members beingconnected by the pin.

In this connection the plunger may be a D-shaped or cylindrical body asshown in Figs. l and 3 with the, eye S located substantially transverserelatively to the axis of the plunger, or it may be a cylindrical memberwith its axis radial to the axis of the pin as shown in Fig. 4 in whichevent the top of the plunger can be part spherical as shown-Alternatively the plunger can be a ball, or a cubical or cylindricalmember with a tapered top, the latter form of plunger being shown inFig. 5 in which the inclined or tapered top 5a normally slopes up fromthe periphery of the pin away from the open end of the pin thusproviding a positive stop opposing withdrawal of the pin as distinctfrom the plungers with radiused tops whichr yield to sufficient tractionon the pin when the pin is to be removed. In Fig. 5 the end 1b of thewire 1 extends slightly beyond the end of the pin I to form a fingerpiece to retract the plunger 5.

The part of the wire or thin rod- 1 which engages in the `plunger may beilattened by pinching it at the lappropriate point or it may' have flatsides throughout its length, e. g. square or triangular section. If itis desired to keep the pin I as solid as possible throughout its length,it may be slotted diametrically instead of hollowed as previouslydescribed, the slot taking the member l, and the plunger 5 being locatedin a diametrical hole intersected by the slot.

Should it be required to have more than one plunger 5 two or moreapertures 4 can be formed in the pin and a corresponding number ofplungers fitted to the member l, or if it is desired to have a plungerat each end of a pin, the pin can be hollow throughout its lengthexcepting for a central solid part bored axially to take the ends of twolengths of wire or narrow gauge rod bent to form two members 1 extendingtowards both ends of the pin and fitted at their ends with plungers 5.Also instead of boring the solid part of the pin as at 8 the inner endof the wire member 1 can be curled or formed into a helix to Wedge it inthe hollow of the pin. The plunger 5 need not be solid as it may be asheet metal stamping closed at' one end, and it can be slotted insteadof bored transversely to receive the member 1.

It will be understood that in the following claims that pin contemplatespins of Widely free to be flexed within the hollow section of said pin,an aperture in the Wall of the hollow section of said pin, a plungeradapted to pass freely through said aperture, said plunger being mountedon the free end of said resilient rod.

2. In a self-locking connecting device, the combination of a pin havingat least one hollow sec` tion open at one end and one solid section, abore extending from the hollow section into the solid section andco-axal with the solid section, a separate resilient rod having one endtting tightly into said bore and having the other end free to be flexedwithin the hollow section of said pin, an aperture in the wall of thehollow section of said pin, a plunger adapted to pass freely throughsaid aperture, said plunger being mounted on the free end of saidresilient rod, said rod normally maintaining said plunger in a positionin which it projects through said aperture.

3. A self-locking device as recited in claim 1 in which the ,resilientrod is bent from the bore toward the wall of said hollow section.`

4. A self-locking device as recited in claim 1 in which the plunger isslidably mounted on the free end of said resilient rod.

JAMES MARTIN.

